• Composites Research
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• v.15 no.5
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• pp.27-34
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• 2002

The purpose of this study is to measure and predict the thermal conductivity of CF3327 plain-weave fabric composite made by Hankuk Fiber, Co. An experiment apparatus based on the comparative method has been made to measure the thermal conductivities of the composite material. Its accuracy was proved by measuring the thermal conductivity of graphite which is well-known. Micro-mechanical approaches are useful to assess the effect of parameters such as fiber and matrix material properties, fiber volume fraction and fabric geometric parameters on the effective material properties of composites. In this study, prediction was based on the concept of three dimensional series-parallel thermal resistance network. Thermal resistance network was applied to unit ceil model that characterized the periodically repeated pattern of a plain weave. The numerical results were compared with experimental one and good agreement was observed. Also, the effects of fiber volume fraction on the thermal conductivity of several composites has been investigated.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2003.11a
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• pp.113-117
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• 2003

In this study is investigated the various properties of concrete with the kinds of stabilizing agent of recycling water and solid content in order to suggest a practical use of recycling water. According to the results, fluidity and air content varies slightly with the kinds of stabilizing agent and solid content, but does not make a big difference. Setting time does not differ remarkably from plain concrete at 20℃, but is shortened with an increase of solid content. Bleeding is reduced more largely in the case of S than in the case of R, and is not influenced by solid content. Compressive strength is equal or decreases in comparison with plain concrete at solid content of I and 50%, and shows the highest value at solid content of 3%. Length change by drying shrinkage is larger than plain concrete at solid content of 5%, and decreases at solid content of I and 3%. Therefore, it proves that the influence of the kinds of stabilizing agent is minute, and solid content is most effective at 3%.

• Journal of Animal Science and Technology
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• v.60 no.4
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• pp.16.1-16.11
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• 2018

Background: In their first days of life, dairy calves in artificial rearing systems often have difficulty using an artificial teat for feeding. Methods: We examined the age at which calves are able to stand up voluntarily and suckle as well as their suckling behavior when presented with a plain dry teat versus a dry teat modified with a presumably attractive odor or taste substance. Single-housed newborn dairy calves (n = 51) were presented for ten consecutive days with a two-minute two-choice test, in which suckling time was recorded for 1) a plain (control) teat versus a glucose-coated teat (taste test) and 2) a plain teat versus a teat with a "Freshly Cut Grass" odor (odor test). Results: On average, the calves were able to stand up voluntarily and suckle from the second or third day of age on. The "Freshly Cut Grass" odor had no significant effect on their suckling behavior. In contrast, the calves showed a significant preference for suckling the glucose-coated teat and displayed a significantly longer total suckling time in the taste test compared to the odor test. There were no significant differences between sexes regarding suckling behavior. Conclusion: The results of the present study show that glucose had a significant effect on the calves' teat preference and significantly increased total suckling time with a dry artificial teat. As such, glucose may increase suckling motivation in non-efficient drinkers or ill calves with low motivation to suckle.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.2
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• pp.133-138
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• 2005

The deformation of sheet metal due to the residual stress during blanking or piercing process, is numerically simulated by means of a commercial finite element code. Two dimensional plain strain problem is solved and then its result is applied to the deformation analysis of the lead frame. The plain strain element is applied to the 2D problem to observe the Von Mises equivalent stress concentration at the both shearing edges. As the punch penetrates into the sheet material, the stress concentration generated on both edges is getting increased to be the shearing surface. The limits of the punching depth applied to the simulation is 16% and 24% of the sheet thickness for the plain strain element and the hexahedral element, respectively. The hexahedral element and the limit of punching depth were applied to the deformation analysis of the lead frame for the blanking process. The FEM results for the lead deformation were very good agreement with the experimental ones. This paper shows that the coarse mesh has enabled to analyze the lead deformation generated due to the blanking mechanism. This simple approach to save the calculation time will be very effective to the design of the blanking tools in industries.

• Fashion & Textile Research Journal
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• v.5 no.4
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• pp.408-412
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• 2003

The micro structure of POY was modified and a wool-like touch yarn of composite fibers with different shrinkage was made. With this yarn 12 different fabrics with wool like touch were prepared. The characteristic physical property changes of the fabrics examined are as follows: 1. In all cases, the initial high shrinkage stages were observed in hot water treatment and the 3D images of complex multilayer of typical doubling fibers with different shrinkage were also observed in hot air treatment of 170C. 2. The tensile strength changes of satin and plain fabrics with the change of twist count showed similar behavior. However, WT's were slightly higher and RT's was lower in twill and satin fabrics than those in plain fabric. 3. Since a slight decrease of B's of twill fabric found with increasing twist count under given experimental condition, it could be influenced on the anti-drape stiffness was decreased and flexibility was increased. 4. A significant decrease of G values was observed in the twist count 800-1000 T.P.M However, in the twist count higher than 1000 T.P.M G values observed were kept nearly constant. 5. MIU of plain and twill fabrics showed a drastic decrease at the twist count higher than 1000 T.P.M.

• Fashion & Textile Research Journal
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• v.10 no.6
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• pp.1023-1035
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• 2008

This study conducted a survey to find out dermatitis patients' preferred garment performance and their sentiment in spring/summer knitwears. SPSS 12.0 program was used for factor analysis, frequency analysis, T-test, ANOVA, and Duncan test. The result was as follows; First, in garments, patients required 'health hygiene', 'practicality in use care', 'skin contact' and 'easy movement'. Especially, 'skin contact' is an important property to be considered in patients' clothes. Second, in garment sensitivity, patients importantly considered 'modesty', 'feminine', 'boldness', 'decency', 'easy movement', 'youth', and 'simplicity'. Third, patients preferred simple and modest plain knitwear in light color with thin and soft fabric such as plain knit. And especially, dot pattern in knitwears should be avoided. Fourth, the preferred style of patients was that 'appropriately fit with suitable ease.' They also preferred 'front closed,' ; 'boat neckline' and 'V neckline'; 'raglan sleeve' and 'set-in sleeve'. For hem trim, they preferred 'rib'. Male preferred simple and plain style with round collar of 'tubular trim' and 'rib trim', while female preferred sophisticated and characteristic style with setin sleeve.

• School Mathematics
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• v.4 no.2
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• pp.283-296
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• 2002

In this study we tried to find the method of using the tangrams and the mosaic puzzles together for learning the elementary geometry in the Korean primary schools. The tangram and the mosaic puzzle activity-panels were developed and the activity-cards for them also were designed. The criteria to be used for the analyses of contents of the activity-cards were developed. We surveyed and analyzed the students' responses, A previous research had insisted that solely using the tangrams were not useful in learning about an obtuse-angled triangle in the elementary geometry (Welchman, 1999), but the combinative uses of the tangrams and the mosaic puzzles were found to extend the limits of the previous study in investigating the figures of the plain diagrams. Actually, the tangrams and the mosaic puzzles helped the students to learn the concepts of several elements of the plain diagrams such as 'angles', 'sides', and 'angular points', with students'operational comparison of the diagrams developed with them. They also provided useful clues in learning the relationship between the 'length' and the 'area' of the Plain diagrams. The students participated in the class with much activities, using the operational learning materials. They also comprehended the concepts and the principles of the elementary geometry more thoroughly, expressing their ideas in spoken or written languages through interactive communication. In conclusion, the tangram and mosaic puzzles can be used for learning the elementary geometry of the primary school level as motivative learning materials, helping students enhance diverse mathematical thinking and discover mathematical principles.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.6
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• pp.1050-1059
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• 2017

Drying processes often cause knitted fabrics to shrink. This study obtains proper drying conditions for in the dryer use that can minimize knitted fabric shrinkage by investigating changes in shrinkage according to drying conditions. The experiment samples were all machine washable plain, mesh, and lacoste knitted fabrics made of 100% cotton. Samples were first washed in a washing machine on a normal cycle. They were then layered on a flat surface in an artificial climate chamber and dried for 24 hours at $20^{\circ}C$ and $40^{\circ}C$, respectively. Shrinkage was measured for 180 minutes at 30 minute intervals after washing. The comparison results of the shrinkage in the washing and drying process indicate that 80.0% and 23.0% shrinkage of plain knitted and lacoste knitted fabrics occurred during the washing process. As the samples dried, the shrinkage of the plain and lacoste knitted fabrics then rapidly increased after approximately 30.0% moisture content. The highest air drying shrinkage occurred over one cycle with insignificant changes in shrinkage after repeated treatments.

• Economic and Environmental Geology
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• v.31 no.5
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• pp.431-446
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• 1998

The calcretes from the Cretaceous Gyeongsang Supergroup in the vicinity of Ulsan city have been examined at five sites (Daedong, Seodong, Ansachon, Deogha, and Mangyangri). In these calcretes, evidences indicating pedogenic origin are recognized. Included are calcite aureoles around detrital grains, pedotubular pores, microstromatactis, circumgranular cracks, fitted structure of adjacent peloids, calcrete ooids, rhizocretions, and calcrete intraclasts. On the basis of calcrete development together with lithofacies, the depositional environments of those deposits are interpreted as lake margin (Daedong deposits), braided to low-sinuosity river (Seodong deposits), braid plain (Ansachon deposits), and meandering river (Deogha and Mangyangri). Stratigraphically, the fluvial deposits of study area show paleoenvironmental change from braided to low-sinuosity river plain under arid climatic condition to meandering river plain under seasonally wet an dry climatic condition. The stratigraphic successions of the Gyeongsang Supergroup of the study area Qacustrine-fluvial-Iacustrine) together with paleoenvironmental change of fluvial deposits suggest that those deposits can be correlated with the Banyaweol-Songnaedong-Geoncheonri formations of the Gyeongsang Supergroup in the western part of the Yangsan Fault.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.2
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• pp.200-211
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• 1998

Heat transfer performance improvement by fin and groovs is studied for condensation of R-11 on integral-fin tubes. Eight tubes with trapczodially shaped integral-fins having fin density from 748 to 1654fpm(fin per meter) and 10, 30 grooves are tested. A plain tube having the same diameter as the finned tubes is also used for comparison. R-11 condensates at saturation state of 32 $^{\circ}C$ on the outside tube surface coded by inside water flow. All of test data are taken at steady state. The heat transfer loop is used for testing singe long tubes and cooling is pumped from a storage tank through filters and folwmeters to the horizontal test section where it is heated by steam condensing on the outside of the tubes. The pressure drop across the test section is measured by menas pressure gauge and manometer. The results obtained in this study is as follows : 1. Based on inside diameter and nominal inside area, overall heat transfer coefficients of finned tube are enhanced up to 1.6 ~ 3.7 times that of a plain tube at a constant Reynolds number. 2. Friction factors are up to 1.6 ~ 2.1 times those of plain tubes. 3. The constant pumping power ratio for the low integral-fin tubes increase directly with the effective area to the nominal area ratio, and with the effective area diameter ratio. 4. A tube having a fin density of 1299fpm and 30 grooves has the best heat transfer performance.